Search results for "reference [key words]"
showing 10 items of 328 documents
Wear modelling in mild steel orthogonal cutting when using uncoated carbide tools
2007
Abstract Wear prediction in machining has been recently studied by FEM although the use of numerical methods for such applications is still a very challenging research issue. In fact, wear phenomenon involves many aspects related to process mechanics which require a very accurate modelling. In other words, only a very punctual code set-up can help the researchers in order to obtain consistent results in FE analysis. The high relative velocity between chip and tool requires effective material models as well as friction modelling at the interface. Moreover the prediction of temperature distribution is another critical task; in the paper some different procedures are discussed. Subsequently a …
Age-Related Reference Ranges for Fetal Foot Length
2000
AIM The aim of this study was to establish age-dependent reference ranges for fetal foot length with gestation as well as for the femur/foot length ratio, based on a mathematical growth model. METHOD In a prospective cross-sectional study of 610 pregnancies with sonographically confirmed gestational age (< 12 weeks' gestation), fetal biometry was performed in addition to measurements of fetal foot length between 12 and 42 completed weeks of gestation. Reference ranges for the fetal foot and for the femur/foot length ratio were constructed with an overall coverage of 90% of the measured data, using a previously established method of determining reference bands for growth parameters. RESULTS …
Study of mycotoxin calibration approaches on the example of trichothecenes analysis from flour
2012
The aim of this study was to evaluate the applicability of different calibration approaches in trichothecenes analysis from wheat flour. Concretely eight trichothecenes (five type B trichothecenes and three type A trichothecenes) were analyzed by matrix solid-phase dispersion (MSPD) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). In the first set of experiments the presence of matrix effects was evaluated; values ranged between 59% and 79%. In the second set of experiments, solutions to compensate these signal suppressions were examined. Different calibration methods showed to tackle matrix effects obtaining values between 69% and 85% for external matrix matched calibration a…
Evaluation of a technical revegetation action performed on foredunes at Devesa de la Albufera, Valencia, Spain
2010
We have evaluated the level of restoration achieved by a technical revegetation action carried out on reconstructed foredunes at the Devesa de la Albufera and compared this level with that achieved by spontaneous succession. Foredunes 1, 3, 6 and 20 y old since revegetated (1, 3, 6 and 20 y, respectively) were considered as spatially separated stages representing a successional trend in the development of the restored plant community. Lower and similar levels of diversity (richness and H´ and Pielou´s indexes) and coverage, respectively, were found on dunes corresponding to the oldest stage of technical revegetation compared with that of the reference site. Diversity and coverage parameters…
Isolation, purification, LC–MS/MS characterization and reactive oxygen species induced by fumonisin B1 in VERO cells
2010
Fumonisins are mycotoxins produced by Fusarium verticillioides that commonly contaminate maize and maize products. The present work shows the results of a comparative study of three different fermentation's techniques (solid and liquid medium of corn and a solid agarized medium) for the production of fumonisins B-1, B-2 and B-3 with strains of F. verticillioides. The solid medium of corn was the most effective in the production of fumonisins, being Fumonisin B-1 the one produced with higher concentration, so the extract obtained by solid fermentation process was used for FB1 purification. Fumonisins characterization and quantification were performed with reversed-phase high-performance liqu…
Thermo-mechanical analysis of irradiation swelling and design optimization of the IFMIF target assembly with bayonet backplate
2017
Abstract The availability of a high flux neutron source for testing candidate materials under irradiation conditions, which will be typically encountered in future fusion power reactors (ITER, DEMO, FPR), is a fundamental step towards the development of fusion energy. To this purpose, the International Fusion Materials Irradiation Facility (IFMIF) represents the reference option to provide the fusion community with a DEMO-relevant neutron source capable of irradiating samples at a damage rate of up to 20 dpa/fpy (in steel) in a volume of 0.5 l. In the framework of the engineering design activities of IFMIF, ENEA is committed in the design of the lithium target assembly (TA) with removable (…
Keypoint descriptor matching with context-based orientation estimation
2014
Abstract This paper presents a matching strategy to improve the discriminative power of histogram-based keypoint descriptors by constraining the range of allowable dominant orientations according to the context of the scene under observation. This can be done when the descriptor uses a circular grid and quantized orientation steps, by computing or providing a global reference orientation based on the feature matches. The proposed matching strategy is compared with the standard approaches used with the SIFT and GLOH descriptors and the recent rotation invariant MROGH and LIOP descriptors. A new evaluation protocol based on an approximated overlap error is presented to provide an effective an…
Hepatobiliary phase hypointensity predicts progression to hepatocellular carcinoma for intermediate-high risk observations, but not time to progressi…
2020
Purpose: To determine whether hepatobiliary phase hypointensity, enhancing “capsule” and size provide prognostic information regarding the risk of progression to hepatocellular carcinoma (HCC), as well as the time to progression, of intermediate to high risk observations ≥ 10 mm with arterial phase hyperenhancement (APHE). Method: This retrospective dual-institution study included 160 LR-3 and 26 LR-4 observations measuring more than 10 mm and having APHE in 136 patients (mean age [SD], 57 [11] years old). A composite reference standard of pathologic analysis and imaging follow-up was used. The prognostic performance of hepatobiliary phase hypointensity, enhancing “capsule” and size (cut-of…
Reference Typing Reportfor Complement Component C3
1998
A comparison of five C3 variant samples has been performed by conventional high-voltage gel electrophoresis in three laboratories (Palermo, Berlin and Mainz). Local designation was shown within SD = ±0.75 mm migration distance in the Mainz laboratory. Methodological modifications by laboratories were not accounted for (cooling temperature, relative mobilities between runs). In parallel, all reference samples were also sequenced after exon-specific amplification. As a result, two variants with identical final designations and two variants with different mobilities were shown to conform at the molecular basis exhibiting an amino acid exchange that causes the corresponding change in relative m…
Calcium in the prevention of postmenopausal osteoporosis: EMAS clinical guide
2017
Abstract Introduction Postmenopausal osteoporosis is a highly prevalent disease. Prevention through lifestyle measures includes an adequate calcium intake. Despite the guidance provided by scientific societies and governmental bodies worldwide, many issues remain unresolved. Aims To provide evidence regarding the impact of calcium intake on the prevention of postmenopausal osteoporosis and critically appraise current guidelines. Materials and methods Literature review and consensus of expert opinion. Results and conclusion The recommended daily intake of calcium varies between 700 and 1200 mg of elemental calcium, depending on the endorsing source. Although calcium can be derived either fro…